1. Field of the Invention
The present invention relates to an information processing apparatus, such as an image forming apparatus with a display device.
2. Description of the Related Art
In recent years, the function of an image forming apparatus such as a multi-function image forming apparatus has advanced remarkably compared to that of a conventional stand-alone copier, etc., which has lead to a great increase in the scale of software installed in the multi-function image forming apparatus. Software greater in scale offers multifunctional capability, but requires a longer time for loading software at the start of the image forming apparatus in proportional to the scale increase. As a result, a time for a user to wait from a point of pressing a start button for starting the image forming apparatus to a point of actual use of the apparatus becomes much longer compared to the conventional stand-alone copier. This poses a problem of impairing user convenience.
A generally adopted solution to this problem is to set a user interface effective before the actual start of the image forming apparatus to reduce an apparent wait time. Specifically, for example, the image forming apparatus carries out control such that a backlight for a display panel (LCD: liquid crystal display) on an operation unit is turned on to output such display as “system is on” when a power supply is started, or such that an image formation command is received actually prior to the start of the apparatus operation. Such control methods reduce a wait time that is bodily sensed by the user.
Depending on a situation, however, display on the display panel may be unnecessary even when the image forming apparatus starts in response to a command from the outside. Reception of a facsimile message late at night is such a case. In this case, an expected job is only the output of received data, so that display on the display panel is considered to be unnecessary. Besides, the image forming apparatus may have a server function of saving image data and exchanging information of the image with an external device via network. This is also a case of no necessity of display, because if the image forming apparatus starts in response to every data access from the outside to turn on the backlight on the operation unit, it may give unnecessary stress to a person who works near the image forming apparatus. To prevent such a situation from happening, effective control may be carried out such that turning on the operation unit at the start of image forming apparatus is allowed in only the minimum necessary starting mode to inhibit display in a starting mode in which display is not required. Quite a few image forming apparatuses, however, does not carry out control over the entire part of the apparatus and control over display operation in an integral manner. This brings difficulty in achieving both objects of execution of display in a short time in a starting mode requiring display and of inhibition of display in a starting mode not requiring display.
A technique has been suggested to achieve above both objects. According to this technique, a dedicated hardware signal for identifying a start factor of an image forming apparatus is exchanged between a system controller controlling the whole operation of the image forming apparatus and an operation unit carrying out display control, and turning on of the operation unit is controlled through this hardware signal (see Japanese Patent Application Laid-Open No. 2006-195253). According to this technique disclosed in Japanese Patent Application Laid-Open No. 2006-195253, when the operation mode returns from an energy-saving mode to a regular operation mode, the operation unit makes a determination on the detail of a return factor causing the mode return from the energy-saving mode as a start factor of the image forming apparatus based on the hardware signal, and turns on a display panel properly to achieve display in a short time and inhibition of unnecessary display.
According to this technique disclosed in Japanese Patent Application Laid-Open No. 2006-195253, however, power supply to the operation unit is cut off in the energy-saving mode and is resumed on mode returning from the energy-saving mode, and the hardware signal is detected when the operation unit starts. Meanwhile, one of the latest versions of image forming apparatuses provides the operation unit with a control function and display data generation function that serve as a means for achieving the operation unit with a higher function and higher display speed to enable display control by the operation unit before the start of the system controller. In such an operation unit, to shorten a return time for mode return from the energy-saving mode, a part of power supply is not cur off even in the energy-saving mode. This operation unit is thus kept being capable of detecting the hardware signal from the system controller at any time. The image forming apparatus equipped with such an operation unit, therefore, is expected to detect the hardware signal in better timing to achieve display in a short time and inhibition of unnecessary display in a more effective manner.